Workshop

Distributed Cryptocurrencies and Consensus Ledgers
“DCCL 2016”
25 July 2016
Chicago, Illinois, USA

Held in conjunction with PODC 2016

The recent global interest in cryptocurrencies was triggered by the rise of Bitcoin, which introduced a public ledger called the blockchain to record the history of its transactions. Bitcoin maintains its blockchain through a decentralized peer-to-peer cryptographic protocol that works without any trusted central authority, but it assumes (at least) that a majority of the computing power in the system is held by honest nodes. Cryptographic techniques ensure the integrity of all transactions in the distributed ledger and new entries are appended through a consensus protocol. Many alternative cryptocurrencies have introduced variations of Bitcoin and proposed alternative designs for consensus ledgers. Novel protocols, known as "smart contracts", are constructed on top of the blockchain, achieving guarantees that were not possible before. Today many financial institutions see the disruptive power of this technology and regard it as a promising alternative to their established business practices, not depending on centralized control, eliminating intermediaries, and enabling new businesses.

Several consensus mechanisms are currently under investigation: On the one hand, Bitcoin's consensus protocol, called "Nakamoto consensus", allows anonymous nodes to participate based on a "proof-of-work". On the other hand, traditional Byzantine consensus and BFT protocols play a role in settings where all nodes are known to each other. Many other systems have been proposed and lie somewhere between these extremes. Distributed knowledge, consistency, and reaching consensus among selfish and mutually distrusting nodes are core topics in the theory and practice of distributed computing. Hence, the popularity of decentralized cryptocurrencies and consensus ledgers creates a unique opportunity for the field to explore this nascent domain and to influence it.

call for contributions


This workshop aims at discussing questions of consistency, concurrency, distributed knowledge, integrity, and reaching consensus in the context of cryptocurrencies and consensus ledgers. The workshop solicits submissions describing current work addressing decentralized cryptocurrencies and consensus ledgers, including analytical results, work on systems, and/or position papers.

Topics of interest include, but are not limited to

  • Distributed consensus among selfish nodes
  • Scalability
  • Mechanisms for consensus ledgers
  • Proof-of-work and alternatives
  • Byzantine fault tolerance
  • Systems implementing distributed ledgers and blockchains
  • Applications of blockchains to distributed computing
  • Nakamoto consensus and protocols based on proof-of-work
  • Smart contracts
  • Anonymity and privacy


Submissions

 

Submissions should be written in English, formatted in single-column letter-sized or A4-sized format, and prepared as a PDF file. Submissions have to include: a title, authors' name and affiliation, and an abstract of up to four pages; additional material may be added in an optional appendix. Papers must be submitted electronically.

The submission deadline is past.

Final papers will be available to participants electronically during the workshop. In order to facilitate resubmission to more formal venues, no archival proceedings will be published. Authors will have the option to upload the final version of their papers on the workshop website.

      Dates      

 

Submission deadline             25 May 2016 AoE (UTC-12)
Acceptance notification             13 June 2016
Workshop             25 July 2016

program committee

       Chair       

 

Christian Cachin, IBM Research – Zurich, Switzerland

 

   Committee   

 

Elli Androulaki, IBM Research – Zurich, Switzerland

Joseph Bonneau, Stanford University, USA

Christian Decker, ETH Zürich

Juan A. Garay, Yahoo Labs, USA

Seth Gilbert, National University of Singapore

Aggelos Kiayias, University of Athens

Marko Vukolić, IBM Research – Zurich, Switzerland

invited speakers


Ittay Eyal, Cornell University, USA

Aniket Kate, Purdue University, USA

Sarah Meiklejohn, University College London, UK

Aviv Zohar, Hebrew University, Israel

program

8:45 - 9:00 Welcome
9:00 - 10:00

Session 1 - Invited talks

Aviv Zohar (Hebrew University)
Bitcoin's security revisited

Ittay Eyal (Cornell University)
Blockchains and Proof of Work

10:00 - 10:30 Coffee break
10:30 - 12:00

Session 2 - Contributed talks

Enhancing Accountability and Trust in Distributed Ledgers
Maurice Herlihy and Mark Moir (Brown University and Oracle Labs)

A Blockchain Based on Gossip? -- A Position Paper
Robbert van Renesse (Cornell University)

Hybrid Consensus: Scalable Permissionless Consensus
Rafael Pass and Elaine Shi (CornellTech, Cornell University, and IC3)

Architecture of the Hyperledger Blockchain Fabric
Christian Cachin (IBM Research)

12:00 - 13:30 Lunch break
13:30 - 15:00

Session 3 - Invited talks

Sarah Meiklejohn (University College London)
Alternatives to Blockchains: Shared Ledgers and Beyond

Aniket Kate (Purdue University)
Distributed IOweYou Credit Networks | Slides

Contributed talk

Efficient Asynchronous Atomic Broadcast
Andrew Miller, Yu Xia, Kyle Croman, Elaine Shi, Dawn Song (University of Maryland, University of Illinois at Urbana-Champaign, Tsinghua University, Cornell University, and University of California at Berkeley)

15:00 - 15:30 Coffee break
15:30 - 16:45

Session 4 - Contributed talks

BVP: Byzantine Vertical Paxos
Ittai Abraham and Dahlia Malkhi (VMware Research)

Extending Existing Blockchains with Virtualchain | Slides
Jude Nelson, Muneeb Ali, Ryan Shea and Michael J. Freedman (Princeton University and Blockstack Labs)

On the Danger of Private Blockchains
Vincent Gramoli (NICTA/Data61 and University of Sydney)

16:45 Final discussion and dlosing

 

registration and venue

The workshop takes place in connection with the PODC 2016 conference.

For registration please use the PODC website and register for the workshop day July 25 or for PODC+Workshops. Please note that the registration fees increase as the event date approaches.

The workshop will be held in downtown Chicago at the Corboy Law Center of Loyola University (Water Tower Campus).

Address 25 East Pearson Street
Chicago
Room 322 CLC

Detailed directions.